Early warning of rice mildew based on gas chromatography-ion mobility spectrometry technology and chemometrics

Rice mildew is a crucial problem for safe storage of high-quality grain. A rapid detection method for early warning of rice mildew is in great need by large-volume barns. In this work, gas chromatography-ion mobility spectrometry (GC-IMS) combined with chemometrics was used to detect mildew odor for realizing early prediction of rice mildew occurrence. 21 characteristic substances from volatile organic compounds of rice samples were identified and selected as features to characterize rice quality change in the mildew process. The obtained peaks gallery corresponded to odor substances showed that there were significant changes in composition and concentration of volatile organic compounds during the mildew process. Principal component analysis and k-means clustering algorithm were combined to build a clustering model and the whole mildew process was divided into four periods. These results confirm the potency of GC-IMS as a reliable analytical screening technique, which can be used to quickly identify the degree of rice mildew.